Aqueous Glycosylation of Unprotected Sucrose Employing Glycosyl Fluorides in the Presence of Calcium Ion and Trimethylamine
作者:Guillaume Pelletier、Aaron Zwicker、C. Liana Allen、Alanna Schepartz、Scott J. Miller
DOI:10.1021/jacs.5b13384
日期:2016.3.9
synthetic glycosylation reaction between sucrosyl acceptors and glycosyl fluoride donors to yield the derived trisaccharides. This reaction proceeds at room temperature in an aqueous solvent mixture. Calcium salts and a tertiary amine base promote the reaction with high site-selectivity for either the 3'-position or 1'-position of the fructofuranoside unit. Because nonenzymatic aqueous oligosaccharide syntheses
Synthesis of 2′,3″,4″-trisphosphate-containing analogs of adenophostin A
作者:Nicole C.R. van Straten、Gijsbert A. van der Marel、Jacques H. van Boom
DOI:10.1016/s0040-4020(97)00308-6
日期:1997.5
Adenophostin A analog 4 was prepared via trimethylsilyl trifluoromethanesulfonate (TMSOTf)-assisted glycosylation of (S)-6-N-diphenylacetyl-9-(2-tert-butyldiphenylsilyloxy-1-hydroxyprop-3-yl)-adenine (11) with trichloroacetimidate donor 12 to give dimer 13. Protective group manipulations on 13 followed by phosphitylation with N,N-diisopropyl-bis-[2-(methylsulfonyl)ethyl] phosphoramidite (17) and in situ oxidation gave, after deprotection, (25)-9-1-(alpha-D-glucopyranosyloxy 3,4-bisphosphate)-2-monophosphate-prop-3-yl}-adenine (4) Condensation of phosphoryloxymethyladenosine 25 with D-arabinitol derivative 21 under the agency of TMSOTf afforded methylene acetal 26. Protective group manipulations (--> 32), phosphorylation, and deprotection yielded 3'-O-(D-arabinitol-4-O-methylene 2,3-bisphosphate)-adenosine 2'-monophosphate (5), a methylene acetal-containing analog of adenophostin A. (C) 1997 Elsevier Science Ltd.